Anti-microbial compositions comprising quaternary organosilane compounds

ABSTRACT

An antimicrobial composition comprising at least two quaternary ammonium compounds selected from: (i) a quaternary ammonium compound having the formula: A4-nSi(R—NHaR1bZ)n and (ii) a quaternary ammonium compound having the formula: NHcR1dZ wherein in each of the at least two quaternary ammonium compounds A, R, R1, a, Z and n are independently selected, and: A is a member selected from the group consisting of alkoxy radicals, alkylether alkoxy radicals, and alkyl radicals; R is a divalent hydrocarbon radical; each R1 is independently a member selected from the group consisting of benzyl, alkyl radicals, alkyl ether hydrocarbon radicals, hydroxyl-containing alkyl radicals, and nitrogen-containing hydrocarbon radicals; Z is a member selected from the group consisting of chloride, bromide, iodide, tosylate, hydroxide, sulfate and phosphate; a is 0, 1 or 2, b is 1, 2 or 3, and the sum of a and b is 3; c is 0, 1, 2 or 3, d is 1, 2, 3 or 4, and the sum of c and d is 4; and n is 1, 2 or 3; and wherein the composition comprises at least two quaternary ammonium compounds of formula (i). A method of making an anti-microbial composition, and a method of reducing the number of micro-organisms on a surface, are disclosed.

The present invention relates to an anti-microbial composition, a methodof making an anti-microbial composition and a method of reducing thenumber of microbes on a surface using an anti-microbial composition.

Many different substances are known for use of disinfectants, both foruse by animals, more particularly humans, and on inanimate surfaces. Inparticular quaternary ammonium compounds are known for this use.

Although they are beneficial in reducing the number of micro-organismson a surface, there is a need for improved anti-microbial compositionswhich will provide improved disinfection.

The present invention seeks to provide an improved anti-microbialcomposition.

According to the present invention there is provided an antimicrobialcomposition comprising at least two quaternary ammonium compoundsselected from:

-   -   (i) a quaternary ammonium compound having the formula:

A_(4-n)Si(R—NH_(a)R¹ _(b)Z)_(n)

-   -   and    -   (ii) a quaternary ammonium compound having the formula:

NH_(c)R¹ _(d)Z

-   -   wherein in each of the at least two quaternary ammonium        compounds A, R, R¹, a, Z and n are independently selected, and:    -   A is a member selected from the group consisting of alkoxy        radicals, alkylether alkoxy radicals, and alkyl radicals;    -   R is a divalent hydrocarbon radical;    -   each R¹ is independently a member selected from the group        consisting of benzyl, alkyl radicals, alkyl ether hydrocarbon        radicals, hydroxyl-containing alkyl radicals, and        nitrogen-containing hydrocarbon radicals;    -   Z is a member selected from the group consisting of chloride,        bromide, iodide, tosylate, hydroxide, sulfate and phosphate;    -   a is 0, 1 or 2, b is 1, 2 or 3, and the sum of a and b is 3;    -   c is 0, 1, 2 or 3, d is 1, 2, 3 or 4, and the sum of c and d is        4; and    -   n is 1, 2 or 3; and    -   wherein the composition comprises at least two quaternary        ammonium compounds of formula (i).

Preferably, A is a member selected from the group consisting of alkoxyradicals of 1 to 10 carbon atoms, alkylether alkoxy radicals of 2 to 10carbon atoms, and alkyl radicals with 1 to 10 carbon atoms; and/or

-   -   R is a divalent hydrocarbon radical with 1 to 10 carbon atoms;        and/or    -   each R¹ is independently a member selected from the group        consisting of benzyl, alkyl radicals with 1 to 30 carbon atoms,        alkyl ether hydrocarbon radicals of 2 to 30 carbon atoms,        hydroxyl-containing alkyl radicals of 1 to 30 carbon atoms, and        nitrogen-containing hydrocarbon radicals of 1 to 30 carbon        atoms.

Conveniently, the composition comprises two quaternary ammoniumcompounds of formula (i) and no quaternary ammonium compounds of formula(ii).

Advantageously, the composition comprises two quaternary ammoniumcompounds of formula (i) and one quaternary ammonium compound of formula(ii).

Preferably, an R¹ group of one of the quaternary ammonium compounds, isdifferent from the R¹ group or groups of the other quaternary ammoniumcompound or compounds.

Conveniently, at least one R¹ group has 18 carbon atoms.

Advantageously, one of the quaternary ammonium compounds is3-(trimethoxysilyl) propyl dimethyl octadecyl ammonium chloride.

Preferably, one of the quaternary ammonium compounds is alkyl silyldimethyl benzyl ammonium chloride.

Conveniently, one of the quaternary ammonium compounds is dioctyl silyldimethyl ammonium bromide.

Advantageously, the composition comprises water and/or ethanol.

Preferably, the composition comprises the quaternary ammonium compoundsin a concentration of from about 0.1 to about 5% by volume, preferablyabout 0.5 to about 2% by volume.

According to an aspect of the invention, there is provided a method ofmaking an anti-microbial composition as defined in any of the precedingparagraphs, the method comprising admixing the at least two quaternaryammonium compounds.

According to an aspect of the invention, there is provided a method ofreducing the number of micro-organisms on a surface, comprisingcontacting said surface with an antimicrobial composition comprising atleast two quaternary ammonium compounds selected from:

-   -   (i) a quaternary ammonium compound having the formula:

A_(4-n)Si(R—NH_(a)R¹ _(b)Z)_(n)

-   -   and    -   (ii) a quaternary ammonium compound having the formula:

NH_(c)R¹ _(d)Z

-   -   wherein in each of the at least two quaternary ammonium        compounds A, R, R¹, a, Z and n are independently selected, and:    -   A is a member selected from the group consisting of alkoxy        radicals of 1 to 10 carbon atoms, alkylether alkoxy radicals of        2 to 10 carbon atoms, and alkyl radicals with 1 to 10 carbon        atoms;    -   R is a divalent hydrocarbon radical with 1 to 10 carbon atoms;    -   each R¹ is independently a member selected from the group        consisting of benzyl, alkyl radicals with 1 to 30 carbon atoms,        alkyl ether hydrocarbon radicals of 2 to 30 carbon atoms,        hydroxyl-containing alkyl radicals of 1 to 30 carbon atoms, and        nitrogen-containing hydrocarbon radicals of 1 to 30 carbon        atoms;    -   Z is a member selected from the group consisting of chloride,        bromide, iodide, tosylate, hydroxide, sulfate and phosphate;    -   a is 0, 1 or 2, b is 1, 2 or 3, and the sum of a and b is 3;    -   c is 0, 1, 2 or 3, d is 1, 2, 3 or 4, and the sum of c and d is        4; and    -   n is 1, 2 or 3; and    -   wherein the composition comprises at least two quaternary        ammonium compounds of formula (i).

Advantageously, A is a member selected from the group consisting ofalkoxy radicals of 1 to 10 carbon atoms, alkylether alkoxy radicals of 2to 10 carbon atoms, and alkyl radicals with 1 to 10 carbon atoms;

-   -   R is a divalent hydrocarbon radical with 1 to 10 carbon atoms;        and    -   each R¹ is independently a member selected from the group        consisting of benzyl, alkyl radicals with 1 to 30 carbon atoms,        alkyl ether hydrocarbon radicals of 2 to 30 carbon atoms,        hydroxyl-containing alkyl radicals of 1 to 30 carbon atoms, and        nitrogen-containing hydrocarbon radicals of 1 to 30 carbon        atoms;

Preferably, the composition is as defined in any of the aboveparagraphs.

Conveniently, the surface is skin.

Advantageously, the surface is an inanimate surface.

Preferably, the anti-microbial composition is used as a spray, foam,mist, fog or wipes.

The present invention will now be described, by way of example, withreference to the following embodiments.

Quaternary ammonium compounds are widely used as disinfectants. Thesecompounds can remain on surfaces to give a persistent effect, allowingthem to remain active on surfaces after cleaning.

Chemically, the quaternary compounds are organically substitutedammonium compounds having four substituents (e.g. alkyl or heterocyclicradicals of a given size or chain length), and an associated anion, suchas a halide, sulfate, or similar moiety. These compounds exhibitantimicrobial characteristics. Some known quaternary ammonium compoundsused in healthcare are alkyl dimethyl benzyl ammonium chloride, didecyldimethyl ammonium chloride, dialkyl dimethyl ammonium chloride, didecyldimethyl ammonium bromide and dioctyl dimethyl ammonium bromide.

The bactericidal action of the quaternary compounds has been attributedto the inactivation of energy-producing enzymes, denaturation ofessential cell proteins, and disruption of the cell membrane.

The quaternary compounds used as hospital disinfectants are generallyfungicidal, bactericidal, and virucidal against lipophilic (enveloped)viruses. More recent quaternary compounds have been found to haveimproved efficacy, for example with activity against spores,Mycobacterium tuberculosis, and virucidal against hydrophilic(nonenveloped) viruses.

Compositions comprising these antimicrobial compounds are used inordinary environmental sanitation of surfaces, especially hard surfaces,such as floors, furniture, and walls. Some specific quaternary ammoniumcompounds are also appropriate to use for disinfecting medical equipmentthat contacts intact skin (e.g., blood pressure cuffs), and foodpreparation surfaces.

EXAMPLES

Tests were performed to verify the efficacy of anti-microbialcompositions in accordance with the invention. The tests were performedon sample patches of worktop material (2 cm² surface) which werecontaminated with a measured amount of a microbe (10,000 CFU Staph.aureus). The samples were then subjected to treatment with compositions(compositions 1, 2 and 3 detailed below) followed by testing for thelevel of microbes with daily cleaning.

Tests were performed with compositions comprising a singlesilicon-containing quaternary ammonium compound, two silicon-containingquaternary ammonium compounds and three silicon-containing quaternaryammonium compounds. The compounds were used as solutions in awater/ethanol mixture. The concentration of each composition was 1% byvolume of the quaternary ammonium compound(s) in 17% ethanol/82% sterilewater.

Composition 1 contained 3-(trimethoxysilyl) propyl dimethyl octadecylammonium chloride. Composition 2 additionally contained alkyl silyldimethyl benzyl ammonium chloride. Composition 3 additionally containeddioctyl silyl dimethyl ammonium bromide.

So, Composition 1 contained a single quaternary ammonium compound.Composition 2 contained two quaternary ammonium compounds. Composition 3contained three quaternary ammonium compounds. All of the quaternaryammonium compounds used in the tests contained silicon.

Comparison of 3 Si Quat compounds Results in CFU per cm² 3 × 2 cm²patches of work top contaminated with 10,000 CFU staph aureus andisolated tests Day of treatment performed prior to 7 14 21 28 3 vigorousdaily cleaning days days days days months Before treatment 9889 Compound1 (single Si 3 3 4 9 167 2889 Quat) Before treatment 9878 Compound 2 (2× Si 0 0 3 3 87 683 Quats) Before treatment 9920 Compound 3 (3 × Si 0 00 0 0 4 Quats)

The test demonstrates the efficacy of compositions of the inventionhaving improved anti-microbial activity. In particular, theanti-microbial activity is long lived as the composition persists on thesurface for a relatively long period of time.

One aspect of the invention is that the composition comprises at leasttwo quaternary ammonium compounds as defined in the claims. At least twoof the quaternary ammonium compounds are silicon-containing quaternaryammonium compounds. The quaternary ammonium compounds are defined below,forming an antimicrobial composition comprising at least two quaternaryammonium compounds selected from:

-   -   (i) a quaternary ammonium compound having the formula:

A_(4-n)Si(R—NH_(a)R¹ _(b)Z)_(n)

-   -   and    -   (ii) a quaternary ammonium compound having the formula:

NH_(c)R¹ _(d)Z

-   -   wherein in each of the at least three quaternary ammonium        compounds A, R, R¹, a, Z and n are independently selected, and:    -   A is a member selected from the group consisting of alkoxy        radicals of 1 to 10 carbon atoms, alkylether alkoxy radicals of        2 to 10 carbon atoms, and alkyl radicals with 1 to 10 carbon        atoms;    -   R is a divalent hydrocarbon radical with 1 to 10 carbon atoms;    -   each R¹ is independently a member selected from the group        consisting of benzyl, alkyl radicals with 1 to 30 carbon atoms,        alkyl ether hydrocarbon radicals of 2 to 30 carbon atoms,        hydroxyl-containing alkyl radicals of 1 to 30 carbon atoms, and        nitrogen-containing hydrocarbon radicals of 1 to 30 carbon        atoms;    -   Z is a member selected from the group consisting of chloride,        bromide, iodide, tosylate, hydroxide, sulfate and phosphate;    -   a is 0, 1 or 2, b is 1, 2 or 3, and the sum of a and b is 3;    -   c is 0, 1, 2 or 3, d is 1, 2, 3 or 4, and the sum of c and d is        4; and    -   n is 1, 2 or 3; and    -   wherein the composition comprises at least two quaternary        ammonium compounds of formula (i).

The compounds of formula (i) are silicon-containing ammonium quaternarycompounds.

The compounds of formula (ii) are quaternary ammonium compounds that donot contain silicon. The focus of the invention is based on compositionsthat contain more than one silicon-containing quaternary ammoniumcompound. The applicants have found that there are several advantages tosuch compositions over prior art compositions. A combination ofsilicon-containing quaternary ammonium compounds provides more effectiveanti-microbial action, both in terms of immediate effect and also longlasting (persistent) effect. The use of more than one silicon-containingquaternary ammonium compound allows for more effective cleaning. Inaddition to the combination of silicon-containing ammonium quaternarycompounds, the compositions of the invention can also contain furthercomponents. These further components can include quaternary ammoniumcompounds that do not contain silicon, and/or other components, such assurfactants.

Preferred compositions contain quaternary compounds in which,independently, A is a member selected from the group consisting ofalkoxy radicals of 1 to 10 carbon atoms, alkylether alkoxy radicals of 2to 10 carbon atoms, and alkyl radicals with 1 to 10 carbon atoms; and/orR is a divalent hydrocarbon radical with 1 to 10 carbon atoms; and/oreach R¹ is independently a member selected from the group consisting ofbenzyl, alkyl radicals with 1 to 30 carbon atoms, alkyl etherhydrocarbon radicals of 2 to 30 carbon atoms, hydroxyl-containing alkylradicals of 1 to 30 carbon atoms, and nitrogen-containing hydrocarbonradicals of 1 to 30 carbon atoms.

Preferred compositions contain at least three quaternary ammoniumcompounds, of which at least two are silicon-containing quaternarycompounds as defined in formula (i) above.

Compositions of the invention include compositions comprising twosilicon-containing quaternary ammonium compounds of formula (i) and noquaternary ammonium compounds of formula (ii); two quaternary ammoniumcompounds of formula (i) and one quaternary ammonium compound of formula(ii); two silicon-containing quaternary ammonium compounds of formula(i) and two silicon-containing quaternary ammonium compounds of formula(ii); two silicon-containing quaternary ammonium compounds of formula(i) and three quaternary ammonium compounds of formula (ii); threesilicon-containing quaternary ammonium compounds of formula (i) and noquaternary ammonium compounds of formula (ii); three silicon-containingquaternary ammonium compounds of formula (i) and one quaternary ammoniumcompound of formula (ii); three silicon-containing quaternary ammoniumcompounds of formula (i) and two quaternary ammonium compounds offormula (ii); three silicon-containing quaternary ammonium compounds offormula (i) and three quaternary ammonium compounds of formula (ii); andso on.

The applicants have found that a composition comprising a mixture ofquaternary ammonium compounds of the invention (containing at least twosilicon-containing ammonium quaternary compounds) is particularlyeffective at reducing and eliminating the number of micro-organisms on asurface. Preferably the ammonium compounds have a mixture of long chaingroups. At least two of the quaternary ammonium compounds in thecomposition are silicon containing quaternary ammonium compound (i.e. acompound of formula (i) as set out above).

As used herein the term micro-organism refers to a pathogen such as avirus or bacteria. Preferably, the micro-organism is a bacteria. Anon-exhaustive list of pathogens is given below:

Bacteria:

Gram Positive Bacteria:

Citrobacter freundii

Citrobacter diversus

Corynebacterium diptheriae

Diplococcus pneumoniae

Micrococcus sp. (I)

Micrococcus sp. (II)

Micrococcus sp. (III)

Mycobacterium spp.

Staphylococcus albus

Staphylococcus aureus

Staphylococcus citrens

Staphylococcus epidermidis

Streptococcus faecalis

Streptococcus pyogenes

Gram Negative Bacteria:

Acinetobacter calcoaceticus

Enterobacter aerogenes

Enterobacter aglomerans (I)

Enterobacter aglomerans (II)

Escherichia coli

Klebsiella pneumoniae

Nisseria gonorrhoeae

Proteus mirabilis

Proteus morganii

Proteus vulgaris

Providencia spp.

Pseudomonas

Pseudomonas aeruginosa

Pseudomonas fragi

Salmonella choleraesuis

Salmonella enteritidis

Salmonella gallinarum

Salmonella paratyphi A

Salmonella schottmuelleri

Salmonella typhimurium

Salmonella typhosa

Serratia marcescens

Shigella flexnerie Type ll

Shigella sonnei

Virbrio cholerae

Viruses:

Adenovirus Type IV

Feline Pneumonitis

Herpes Simplex Type I & ll

HIV-1 (AIDS)

Influenza A (Japan)

Influenza A2 (Aichi)

Influenza A2 (Hong Kong)

Norovirus

Parinfluenza (Sendai)

Poliovirus

Reovirus

Respiratory Synctia

Fungi and Mould:

Alternaria altemata

Asperigillus niger

Aureobasidium pullulans

Candida albicans

Cladosporium cladosporioides

Drechslera australiensis

Gliomastix cerealis

Microsporum audouinii

Monilia grisea

Phoma fimeti

Pithomyces chartarum

Scolecobasidium humicola

Trychophyton interdigitale

Trychophyton mentagrophytes

The compositions of the invention generally contain the quaternaryammonium compounds in a solvent. The solvent is preferably aqueous, andmore preferably a mixture of water and alcohol, preferably ethanol. Thecomposition may contain methanol, for example as a stabiliser.

The terminology used herein is for describing particular embodiments andis not intended to be limiting.

The term “pathogen” as used herein also includes gram positive and gramnegative bacteria, viruses and fungi, including yeasts and moulds.

The term “alkyl” as used herein refers to a straight chain or branchedsaturated hydrocarbon.

The term “alkylether alkoxy” as used herein refers to an alkyl ethermoiety containing carbon-oxygen-carbon bonds and having a terminaloxygen atom bonded to the silicon atom.

The term “alkyl ether” group as used herein refers to an alkyl group asdefined above containing within the carbon chain a carbon-oxygen-carbonlinkage. Polyethers are also included in this definition as being alkylgroups containing more than one carbon-oxygen-carbon linkage.

The term “alkoxy” as used herein refers to alkyl groups defined as abovewhich have a terminal carbon-oxygen linkage. “Lower” used herein inreference to alkyl, alkoxy and alcohols, indicates species and compoundshaving 1 to 4 carbons.

The term “antimicrobial” as used herein is used in reference to theability of the compound composition or article to eliminate, remove,inactivate, kill or reduce microorganisms such as bacteria, viruses,fungi, moulds, yeasts and spores. The term antimicrobial as used hereinto imply reduction and elimination of the growth and formation ofmicroorganisms such as described above.

The compositions of the invention can be used in many differentapplications in order to reduce and/or eliminate the number ofpathogens. In particular they can be used on inanimate surfaces. Theycan be used in healthcare environments, in the home and other situationsin order to disinfect surfaces. Such applications include the foodindustry, water treatment and hospitals. The Applicants have found thatthe application of the composition to a surface reduces substantiallythe number of pathogens within a very short period of time. In addition,the composition produces a long-lasting pathogenic effect from theapplication of the composition to a surface. The quaternary ammoniumcompounds of the compositions of the invention persist on the surfaceeven if they are subjected to normal use, for a period of time. Thecompositions have been found to be effective against viruses, andagainst norovirus in particular.

The anti-microbial compositions of the invention may be used in manydifferent ways. Preferably, the composition of the invention is aliquid. For example, the composition could be used as a spray, to besprayed onto surfaces. The surfaces are then either be left for thecomposition to dry, or the composition may be wiped with a clean clothor other implement and then left to dry. The composition of theinvention can also be provided as a foam, to be applied to a surface.The composition could be released from a container which forms the foam,for example by entraining air. The composition may optionally containcomponents to aid in the formation of the foam. The composition of theinvention may also be used in the form of a wetted wipe. So, a wipeimpregnated with the composition may be used to wipe a surface. Anotherway of applying the composition is through the generation of a fog. Inother words, small liquid particles of the composition of the inventionmay be formed to generate a mist or fog, which can then contact surfacesto be disinfected.

It is believed that the compositions of the invention become moreeffective some time after being applied to a surface and left to dry.Without being bound by theory, the Applicants believe that at least someof the components of the composition may become bonded to the surface,giving a long lasting persistent anti-microbial effect. This could be,in the case of a silicon-containing quaternary ammonium compound,hydrolysis in the formation of a bond with the material of the surfacebeing disinfected.

It is believed that the mix of at least two different quaternaryammonium compounds is a factor in the efficacy of the compositions ofthe invention. In particular, it is believed that having differentorganic groups, especially of different chain lengths, enhancesefficacy. The compounds of the invention contain at least two differentquaternary ammonium compounds, of which at least two aresilicon-containing quaternary ammonium compounds as defined in formula(i) in the claims. Preferably, the composition contains at least twoquaternary ammonium compounds, each having at least one pendant grouphaving at least eight carbon atoms. More preferably, each of the atleast two quaternary ammonium compounds has such an organic moiety whichhas a different chain length from the other groups in the otherquaternary ammonium compounds in the composition.

It is preferred for the quaternary ammonium compounds used in theinvention to be provided in an aqueous solvent. Although the solventcould be essentially water, it is preferred that the solvent compriseswater and an alcohol, such as ethanol. This reduces the drying time ofthe composition when applied to a surface. If desired, the compositioncan contain other optional components.

Compositions of the invention can be made, for example, by admixing theat least two quaternary ammonium compounds with a solvent. Thecompositions may be provided in a concentration which is ready to use,or may be provided in the concentrated form, ready for dilution to amore appropriate concentration when needed.

In addition to disinfecting inanimate surfaces, the compositions of theinvention could be used to disinfect a surface of the living body, forexample the skin.

1. An antimicrobial composition comprising at least two quaternaryammonium compounds of Formula (i) and at least one quaternary ammoniumcompound of formula (ii) wherein:A_(4-n)Si(R—NH_(a)R¹ _(b)Z)_(n)   (i)NH_(c)R¹ _(d)Z   (ii) wherein in each of the quaternary ammoniumcompounds of Formula (i) and Formula (ii), A, R, R¹, a, and n areindependently selected, and: A is a member selected from the groupconsisting of alkoxy radicals, alkylether alkoxy radicals, and alkylradicals; R is a divalent hydrocarbon radical; each R¹ is independentlya member selected from the group consisting of benzyl, alkyl radicals,alkyl ether hydrocarbon radicals, hydroxyl-containing alkyl radicals,and nitrogen-containing hydrocarbon radicals; Z is a member selectedfrom the group consisting of chloride, bromide, iodide, tosylate,hydroxide, sulfate, and phosphate; a is 0, 1 or 2, b is 1, 2 or 3, andthe sum of a and b is 3; c is 0, 1, 2 or 3, d is 1, 2, 3 or 4, and thesum of c and d is 4; and n is 1, 2 or
 3. 2. The composition of claim 1,wherein; A is a member selected from the group consisting of alkoxyradicals of 1 to 10 carbon atoms, alkylether alkoxy radicals of 2 to 10carbon atoms, and alkyl radicals with 1 to 10 carbon atoms; and/or R isa divalent hydrocarbon radical with 1 to 10 carbon atoms; and/or each R¹is independently a member selected from the group consisting of benzyl,alkyl radicals with 1 to 30 carbon atoms, alkyl ether hydrocarbonradicals of 2 to 30 carbon atoms, hydroxyl-containing alkyl radicals of1 to 30 carbon atoms, and nitrogen-containing hydrocarbon radicals of 1to 30 carbon atoms.
 3. The composition of claim 1 comprising threequaternary ammonium compounds of formula (i) and one quaternary ammoniumcompound of formula (ii).
 4. (canceled)
 5. The composition of claim 1,wherein an R¹ group of one of the quaternary ammonium compounds, isdifferent from the R¹ group or groups of the other quaternary ammoniumcompound or compounds.
 6. The composition of claim 1, wherein at leastone R¹ group has 18 carbon atoms.
 7. The composition of claim 1, whereinone of the quaternary ammonium compounds is 3-(trimethoxysilyl) propyldimethyl octadecyl ammonium chloride.
 8. The composition of claim 1,wherein one of the quaternary ammonium compounds is alkyl silyl dimethylbenzyl ammonium chloride.
 9. The composition of claim 1, wherein one ofthe quaternary ammonium compounds is dioctyl silyl dimethyl ammoniumbromide.
 10. The composition of claim 1 further comprising water and/orethanol.
 11. The composition of claim 1 comprising the quaternaryammonium compounds in a concentration of from about 0.1 to about 5% byvolume.
 12. A method of making the anti-microbial of claim 1, the methodcomprising admixing the quaternary ammonium compounds of Formula (i) and(ii).
 13. A method of reducing the number of micro-organisms on asurface, the method comprising contacting said surface with anantimicrobial composition comprising at least two quaternary ammoniumcompounds of Formula (i) and at least one quaternary ammonium compoundof Formula (ii): wherein:A_(4-n)Si(R—NH_(a)R¹ _(b)Z)_(n)   (i)NH_(c)R¹ _(d)Z   (ii) wherein in each of the quaternary ammoniumcompounds of Formula (i) and Formula (ii), A, R, R¹, a, Z, and n areindependently selected, and: A is a member selected from the groupconsisting of alkoxy radicals of 1 to 10 carbon atoms, alkylether alkoxyradicals of 2 to 10 carbon atoms, and alkyl radicals with 1 to 10 carbonatoms; R is a divalent hydrocarbon radical with 1 to 10 carbon atoms;each R¹ is independently a member selected from the group consisting ofbenzyl, alkyl radicals with 1 to 30 carbon atoms, alkyl etherhydrocarbon radicals of 2 to 30 carbon atoms, hydroxyl-containing alkylradicals of 1 to 30 carbon atoms, and nitrogen-containing hydrocarbonradicals of 1 to 30 carbon atoms; Z is a member selected from the groupconsisting of chloride, bromide, iodide, tosylate, hydroxide, sulfate,and phosphate; a is 0, 1 or 2, b is 1, 2 or 3, and the sum of a and b is3; c is 0, 1, 2 or 3, d is 1, 2, 3 or 4, and the sum of c and d is 4;and n is 1, 2 or
 3. 14. (canceled)
 15. The method of claim 13, whereinthe surface is skin.
 16. The method of claim 13, wherein the surface isan inanimate surface.
 17. The method of claim 13, wherein theanti-microbial composition is a spray, foam, mist, fog, or wipe.
 18. Thecomposition of claim 1 comprising the quaternary ammonium compounds in aconcentration of from about 0.5 to about 2% by volume.